The given dissociation constant Ka is not relevant for HCl in this case, as HCl is a strong acid and dissociates completely in water. Therefore, we can directly calculate the pH of the solution using the concentration of HCl.The pH of a solution is calculated using the formula:pH = -log10[H+]Since HCl is a strong acid and dissociates completely, the concentration of H+ ions will be equal to the concentration of HCl. In this case, the concentration of HCl is 0.1 M.pH = -log10 0.1 pH = - -1 pH = 1The pH of the 0.1 M HCl solution is 1.